Introduction
Stepdance is a motion control operating system that scaffolds a wide range of modular software components. These can do things like:
- real-time control of motors from encoders and potentiometers
- emulate standard motion controllers to interpret pre-planned motion formats like g-code and AxiDraw
- record and replay motion streams
- apply filters such as scaling and rotation
- generate a host of motion signals including transiting to a position, constant velocity, sinusoidal position, etc.
- convert between coordinate systems, e.g. polar and cartesian
- mix signal sources in real-time
Most of the stepdance framework is interrupt-driven and operates in the background, by taking advantage of the relatively massive computing power of the Teensy 4/4.1 (based on the iMXRT1062).
In this documentation we describe the overall framework, the currently available elements, and how to connect everything together.
Overview
The Stepdance library provides a flexible architecture for motion control through several key components:
- BlockPorts: Unified interface for connecting components and routing data between them (see BlockPort and Core Components)
- Channels: Position state management and step/direction signal generation (see Channel and Channels)
- Input/Output Ports: Physical hardware interface for receiving and transmitting motion signals (see InputPort, OutputPort, and Input/Output Modules)
- Generators: Motion pattern and trajectory generation (see Generators)
- Kinematics: Coordinate system transformations (Cartesian, polar, CoreXY, etc.) (see Kinematics)
- Filters: Signal smoothing and noise reduction (see Filters)
- Interfaces: External protocol support (G-code, EiBotBoard, etc.) (see GCodeInterface, Eibotboard, and External Interfaces)
- Recording: Motion recording and playback functionality (see FourTrackRecorder, FourTrackPlayer, and Recording and Playback)
- Inputs: Physical input device handling (see AnalogInput, Button, Encoder, and Input Devices)
Getting Started
For a complete guide to getting started with Stepdance, see the Getting Started with Stepdance page.
To get started with Stepdance programming:
- Understand BlockPorts: BlockPorts are the fundamental communication mechanism between components. See the BlockPort class and Core Components module for details.
- Configure Output Ports: Set up your physical output ports to send step/direction signals. See the OutputPort class and Input/Output Modules module for configuration.
- Create Channels: Channels drive motors to target positions. See the Channel class and Channels module for setup and usage.
- Add Motion Sources: Connect input ports, generators, or other motion sources to your channels using BlockPort mapping. See Generators and Input Devices for available sources.
Examples
For complete working examples, see the Stepdance Example Index page which includes examples organized by category:
- Core examples (analog input, encoders, I/O tests)
- Motion control examples (pantograph, wheelbot, harmonograph)
- Plotting examples (AxiDraw interface, G-code)
- 3D printer examples (clay printer, extrusion)
- And more...
Example code snippets are also provided throughout the documentation for individual classes.
Module Organization
The library is organized into functional modules:
- core - Core framework components
- io - Hardware I/O interfaces
- channels - Position control
- generators - Motion generation
- kinematics - Coordinate transformations
- filters - Signal processing
- interfaces - External protocols
- recording - Motion recording and playback
- inputs - Physical input devices
Supported Hardware
Stepdance runs on Teensy microcontrollers and supports:
- Basic Modules (single input port)
- Machine Controller Modules (multiple I/O ports)
Additional Resources
1.14.0